EP0162094A1 - Procede de diminution des emissions gazeuses et particulaires et de recuperation de chaleur pendant la combustion ou la fusion de substances contenant des cendres et du soufre - Google Patents

Procede de diminution des emissions gazeuses et particulaires et de recuperation de chaleur pendant la combustion ou la fusion de substances contenant des cendres et du soufre

Info

Publication number
EP0162094A1
EP0162094A1 EP85900110A EP85900110A EP0162094A1 EP 0162094 A1 EP0162094 A1 EP 0162094A1 EP 85900110 A EP85900110 A EP 85900110A EP 85900110 A EP85900110 A EP 85900110A EP 0162094 A1 EP0162094 A1 EP 0162094A1
Authority
EP
European Patent Office
Prior art keywords
gases
combustion
ash
particle
smelting
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP85900110A
Other languages
German (de)
English (en)
Inventor
Pertti Sarkomaa
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Repola Oy
Original Assignee
Rauma Repola Oy
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Rauma Repola Oy filed Critical Rauma Repola Oy
Publication of EP0162094A1 publication Critical patent/EP0162094A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23B—METHODS OR APPARATUS FOR COMBUSTION USING ONLY SOLID FUEL
    • F23B90/00—Combustion methods not related to a particular type of apparatus
    • F23B90/04—Combustion methods not related to a particular type of apparatus including secondary combustion
    • F23B90/06—Combustion methods not related to a particular type of apparatus including secondary combustion the primary combustion being a gasification or pyrolysis in a reductive atmosphere
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J1/00—Removing ash, clinker, or slag from combustion chambers
    • F23J1/08—Liquid slag removal
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J15/00—Arrangements of devices for treating smoke or fumes
    • F23J15/02—Arrangements of devices for treating smoke or fumes of purifiers, e.g. for removing noxious material
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J15/00—Arrangements of devices for treating smoke or fumes
    • F23J15/02—Arrangements of devices for treating smoke or fumes of purifiers, e.g. for removing noxious material
    • F23J15/022—Arrangements of devices for treating smoke or fumes of purifiers, e.g. for removing noxious material for removing solid particulate material from the gasflow
    • F23J15/027—Arrangements of devices for treating smoke or fumes of purifiers, e.g. for removing noxious material for removing solid particulate material from the gasflow using cyclone separators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J15/00—Arrangements of devices for treating smoke or fumes
    • F23J15/06—Arrangements of devices for treating smoke or fumes of coolers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E20/00—Combustion technologies with mitigation potential
    • Y02E20/30—Technologies for a more efficient combustion or heat usage

Definitions

  • the present invention relates to a method for producing energy from fuels containing ash (e.g. coal , peat, wood, bark) or for smelting concentrates or other substances in such a way that the inorganic compounds in the flue gases (the ash of fuels among others) are separated partly within the combustion chamber or smelting chamber and eventual ly in a smelt cyclone disposed after said chamber, but mainly within a so cal led particle cooler disposed after the com ⁇ bustion or smelting chamber,, into which cooler the flue gas enters at such a high temperature that the ash is either molten or vapourized.
  • ash e.g. coal , peat, wood, bark
  • smelting concentrates or other substances in such a way that the inorganic compounds in the flue gases (the ash of fuels among others) are separated partly within the combustion chamber or smelting chamber and eventual ly in a smelt cyclone disposed after said chamber, but mainly within
  • the conditions within the particle cooler can be chosen regardless of the combustion or smelting method so that the separation of the inorganic compounds and the removal of the environmental ly or othei— wise harmful gaseous oxides (SO and NO among others) can be carried out in the most effective way.
  • SO and NO among others harmful gaseous oxides
  • Fluidized bed combustion suitable for al lmost al l fuels
  • Coal is mil led into fine powder with an average particle size of 50 to 150 ⁇ m and is burned by means of several diffusion burners in a combustion chamber or furnace of a boi ler.
  • Fluidized bed combustion has rapidly become more general in units burning sol id fuels and having a thermal capacity below 100 MW as it is suitable for very different kinds of fules, primari ly due to its stabi l ity which is based on its wide temperature capacity.
  • the temperature can be maintained almost stable in the entire combustion chamber, which makes a simultaneous
  • the decomposing of sulphate, smelting of ash and the requirement for efficient combustion l imit the temperature range of combustion and SO absorption in the same reactor to the narrow range of 850 C - T - 900 .
  • the ash bound to the so cal led organic matter of the fuel cannot be recovered notably by any method based on fluidized bed combustion, but the boi lers always have to be provided with dust separation equipment. Due to the narrow temperature range, the turndown ratio of the boi ler is l imited and a compromise between the combustion efficiency and a good SO absorption has to be made .
  • European patent appl ication 27 280 describes a method of improving dust separation by agglomerating the ash particles of a secondary cyclone in a local hot spot of the fluid bed.
  • Ash agglomeration in a local hot spot of the bed is to be considered as a known method with several sl ightly varying appl ications. It is characteristic of al l these methods that most of the fluid bed operates at temperatures under the ash smelting or sintering temperature and the agglomeration of the ash is carried out by increasing the temperature local ly.
  • US Patent 4,198,212 describes a method of treating the product gas of coal gasification, wherein the organic im ⁇ purities (tars, acids, coal) contained by the fluid bed gasifier are separated by leading the gases through a cooled fluid bed, whereupon the impurities condensate on the sur ⁇ face of the bed material .
  • the bed material used is inert coal .
  • a corresponding separation capacity may be achieved in a conventional counter-flow gasifier, in which the gases are discharged through a bed formed by new gasification material .
  • Stoker combustion is suitable only for sol id, lumped fuels.
  • a proper preparation of the fuel e.g. pel letizing of peat
  • Stoker combustion cannot be appl ied in high-capacity units, because the ash easi ly smelts on the stoker and thus causes opera ⁇ tional disturbances.
  • gaseous emissions With regard to gaseous emissions.
  • O PI stoker combustion is not a good choise, since the binding of the SO compounds into metal sulphates is in practise not possible. Also with- regard to nitric oxi des , • convent i ona I stoker combustion cannot be recommended, since the general control labi l ity of a stoker combustion process is poor. There are always local areas which have s imu I ataneous ly a high temperature and excess oxygen. In practise the flue gases of stoker boi lers also require dust separation equip ⁇ ment .
  • the method in accordance with the patent appl ication is characterized in that combustion or smelting is carried out in a manner known per se so that the inorganic compounds are either smelted or vapourized.
  • the combustion can be performed as conventional combustion, suspension combustion or multi-stage combustion.
  • multi-stage combustion the sol id fuel is first gasified and the combustion is then continued by adding oxygen into the gasification products so that the ash of the gas entering the particle cooler is either molten or vapourized.
  • Conventional fluidized bed combustion cannot be used instead of the combustion of the method according to the invention, since the smelting of the ash would cause sintering of the bed.
  • a fluidized bed gasifier can be used as the first stage.
  • Staged combustion can be recommended, since it does not require pulverizing of the fuel (the average particle size in dust combustion is approx. ⁇ 150 ⁇ m) and in the gasification stage the nitrogen of the fuel can be trans ⁇ formed into molecular nitrogen (N.,) . It is known that molecular nitrogen (N-) is transformed into nitrogen oxide slower than nitrogen bound in the fuel . Furthermore, the excess oxygen in the combustion fol lowing the gasification can be maintained a * t a low level , since the compounds pre ⁇ sent in the last combustion stage are mainly gaseous.
  • the gases containing vapourized and smolten inorganic compounds are conveyed to a particle cooler in which the inorganic melts and vapours of the gases are layered on the surface of the particles in a sol id, state.
  • the sol id material forms spherical pel lets which are suitable for further processing.
  • the particle material can be chosen so (e.g. CaCO-) that the oxides bind themselves to the material (e.g. CaSOdefinite) .
  • the temperature of the particles is set by means of cool ing to such a range - in the absorp ⁇ tion of sulphur typical ly 500 to 900 °C - that the condi ⁇ tions are favourable for the noxious substance to react with the particle material .
  • the particle cooler mentioned in this invention is an apparatus in which particles colder than the gas are mixed with the gas, whereby the molten and vapourized ash con ⁇ tained by the gases is agglomerated on the surface of the particles in a sol id state.
  • the particles are cooled inside and/or outside the particle cooler.
  • the wal ls of the chamber of the particle cooler can be uncoo I ed or partly or entirely cooled.
  • a conventional fluidized bed cooler or a circulating fluidized bed cooler are examples of a particle cooler, but the operation of a particle cooler can be achieved by means of various arrange ⁇ ments of the gas and particle flows and cool ing etc.
  • the particle cooler can be a para I 1 e I -f1 ow cooler, a counter- flow cooler or a para 11 e I -fi ow/countei—flow cooler and the direction of the particle flow can be either perpendicular to or obl ique with regard to the direction of the gas flow.
  • the longitudinal axis of the chamber of the particle cooler is preferably in a vertical direction, but it can also be in horizontal or incl irred position.
  • the present invention offers five essential advantages
  • Third, the method solves the problem of the vapourized ash compounds present in pressurized combustion of sol id fuels in gas turbine appl ications.
  • the boi ler and the boi ler plant are smal ler and there is no need for a big combustion chamber for the cool ing of the gases by means of radiation to a temperature below the smelting point of the ash, which is an essential advantage, especial ly with regard to a large boi ler.
  • the combustion can be carried out under optimum conditions for each fuel separately from sulfur absorption and, as far as is required, from the recovery of heat.
  • Fig. 1 i l lustrates a combustion method for the combus ⁇ tion of fuels having a low ash content
  • Fig. 2 i l lustrates a combustion method for two-stage combustion of fuels having a high ash content
  • Fig. 3 i l lustrates a method in accordance with the invention for the smelting of oxide concentrates
  • Fig. 4 illustrates a method in accordance with the invention for the combustion of sulphur containing fuel having a low ash conrtent
  • Fig. 5 illustrates a method in accordance with the invention applied in an open gasturbine process using a soI id fueI .
  • Fig. 1 illustrates a combustion method for fuels having a low ash content.
  • the burning of the fuel takes place in a combustion chamber 1 into which fuel and oxygen are brought.
  • the combustion is carried out at such a temperature that the ash contained by the gas which is conducted to the lower chamber 2 is vapourized or molten.
  • a heat recovery part is disposed above a discharge opening 3 of the chamber 2.
  • Said heat recovery part comprises a particle cooler 4 and eventually heat surfaces 5.
  • the temperature of the particle cooler 4 is chosen so that the inorganic vapours and melts contained by the gases are agglomerated on the surface of the particles in a solid state. If required, an efficient separation of sulphur oxides from the gases can be achieved in the particle cooler 4.
  • the clean flue gases are discharged through an opening 9.
  • the inorganic matter which has been separated in the particle cooler can be removed through a separate outlet 10 of the cooler or together with the melt separated into the chamber 2.
  • the molten ash flows through an opening 6 on the bottom of the chamber 2 to a granulating chamber 7 and is discharged together with the cooling water by means of a pump 8.
  • Fig. 2 illustrates a method according to the invention for two-stage combustion of a fuel having a high ash content.
  • the gasifying (under-stoichiometric) combustion is carried out in a chamber 11 in such a way that ash may remain in a solid form in this stage. Excess air required
  • O PI for further combustion is brought to the process via a connecting means 12 disposed between the gasifying chamber 11 and a smelt cyclone 13.
  • a connecting means 12 disposed between the gasifying chamber 11 and a smelt cyclone 13.
  • the molten ash separated in the smelt cyclone 13 flows through an opening 16 to a granulation chamber 17.
  • the ash separated in the particle cooler is removed either through a separate outlet means 20 or from the bottom of the granulation chamber 17 by means of a pump 18.
  • the heat recovery part comprises a particle cooler 14 and eventual ly a secondary cooler 15. Clean gases are discharged through an outlet opening 19. .
  • Fig. 3 i l lustrates a method in accordance with the invention for the smelting of a concentrate or other soiid substance.
  • Fuel the matter to be smelted and the oxidizer are brought into a combustion chamber 21 and the combustion is carried out so that the sol id material smelts.
  • the combustion in the chamber 21 can be of an under-sto i chi ometr i c nature.
  • Oxygen containing gas is brought into the reaction through a connecting duct 22 disposed between the chamber 21 and a smelt cyclone 23.
  • the viscosity of the molten inorganic compounds contained by the gases is suitable for the smelt cyclone 23.
  • the molten compounds are separated mainly on the wal ls and flow further down to a lower furnace 27 where the phase separa ⁇ tion of the smelt takes place. Slag is discharged through an opening 26 and the heavier phase through an opening 28.
  • Gases containing vapours and melts are conveyed to a particle separator 24 where the vapours and the melts stick onto the surface of the particles in a sol id, state.
  • Pel le- t i zed inorganic matter is discharged through an outlet opening 30.
  • Clean gases are cooled further in a cooler 25, if required, and removed through an outlet opening 29.
  • the smelting method can also be used in the smelting of stone and glass, wherefore it can be appl ied e.g. in the insulation industry in the manufacture of glass wool and mineral wool .
  • the combustible gases formed in the smelting of the wool process can be uti l ized in the drying stages of the process, since when using the smelting in accordance with the invention they are clean enough.
  • Fig. 4 i l lustrates a method in accordance with the invention for the combustion of high-sulphur fuels having a low ash content.
  • Combustion is carried out in a chamber 31 as conventional flame combustion.
  • Flue gases containing sulphur oxides are conveyed to a particle cooler 34 where the temperature of the particles has been chosen so that SO sets into calcium sulphate and simultaneousl the vapourized ash compounds (e.g. vanadium compounds) are condensated on the surface of the particles.
  • the Ca-bearing material required for the absorption of sulphur is introduced through an inlet opening 32.
  • the material containing sulphate is discharged through an outlet opening 33.
  • the cleaned gases can be cooled further in a cooler 35, if required.
  • thermal energy recovered in the coolers of Figs. 1 to 4 can be used e.g. in processes, power plants and for heating.
  • Fig. 5 i l lustrates the method in accordance with the invention appl ied in an open gasturbine process which uses sol id fuels.
  • a compressor 41 compresses air, part of which is used in a gasifier 42 as an oxidizer. Most of the air is conducted through cool ing pipes 43 of the gasifier and cool ing pipes 44 of the particle cooler into a combustion chamber 45 of the open gasturbine to act there as combustion air or, a minor part of the air, as secondary air of the staged combustion so that the ash contained by the gas is in the form of a vapour or a melt having such a viscosity that the separation of molten ash in a smelt cyclone 47 is efficient.
  • ash is removed through an opening 48 on the bottom of the cyclone.
  • Gases containing molten ash and vapours are conveyed through an opening 49 to a particle cooler 50 where the molten and vapourized ash sti l l con-, tained by the gases (containing e.g. alkal i and vanadium compounds) sticks on the surfaces of the particles mainly in the lower part of the particle cooler.
  • gases containing e.g. alkal i and vanadium compounds
  • Material is introduced into the particle cooler through an opening 51 and discharged from the particle cooler through an opening 52.
  • the cleaned gases are conducted through an opening 53 to the -combustion chamber 45 of the open gasturbine. If required, also air 54 is conducted to said chamber from the compressor 41.
  • Gases 55 of the combustion chamber are conveyed to a gasturbine 56 which rotates both the compressor 41 and a generator 57.
  • Clean flue gases having a low sulphur content are pre ⁇ ferably conveyed to a flue gas boi ler or they can be used as such for drying or heating.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Thermal Sciences (AREA)
  • Treating Waste Gases (AREA)
  • Fluidized-Bed Combustion And Resonant Combustion (AREA)

Abstract

Procédé de combustion de combustibles contenant des cendres et du soufre ou de fusion de substances et de récupération de chaleur, si bien que des composés inorganiques (cendres) et, si on le désire, des oxydes de soufre sont séparés simultanément des gaz. Dans ce procédé, la combustion ou la fusion est effectuée d'une manière connue per se par l'introduction d'oxygène au cours d'une ou de plusieurs étapes. Les gaz contenant des fondus et des vapeurs peuvent être purifiés au moyen d'un cyclone de fusion avant la partie de purification et de récupération de chaleur. Dans ce procédé, les gaz contenant des fondus et des vapeurs sont amenés à un refroidisseur de particules où la température des particules a été choisie, généralement <= 900oC, de telle manière que les fondus et les vapeurs se fixent sur la surface des particules sous la forme d'une couche solide. Si les nouvelles particules introduites dans le refroidisseur de particules sont partiellement ou entièrement à base d'un matériau formant du sulfate, il est possible de séparer simultanément les oxydes de soufre des gaz.
EP85900110A 1983-11-23 1984-11-22 Procede de diminution des emissions gazeuses et particulaires et de recuperation de chaleur pendant la combustion ou la fusion de substances contenant des cendres et du soufre Withdrawn EP0162094A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI834283 1983-11-23
FI834283A FI84561B (fi) 1983-11-23 1983-11-23 Foerfarande foer foerminskning av fasta och gasformiga emissioner och foer vaermeaotervinning vid foerbraenning och smaeltning av aemnen innehaollande aska och svavel.

Publications (1)

Publication Number Publication Date
EP0162094A1 true EP0162094A1 (fr) 1985-11-27

Family

ID=8518113

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85900110A Withdrawn EP0162094A1 (fr) 1983-11-23 1984-11-22 Procede de diminution des emissions gazeuses et particulaires et de recuperation de chaleur pendant la combustion ou la fusion de substances contenant des cendres et du soufre

Country Status (3)

Country Link
EP (1) EP0162094A1 (fr)
FI (1) FI84561B (fr)
WO (1) WO1985002454A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT393970B (de) * 1990-05-02 1992-01-10 Sgp Va Energie Umwelt Verfahren zur verbrennung von gasen, welche mit staeuben beladen sind

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3230472A1 (de) * 1982-08-16 1984-02-16 Deutsche Kommunal-Anlagen Miete GmbH, 8000 München Verfahren und vorrichtung zum reinigen von pyrolysegasen

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO8502454A1 *

Also Published As

Publication number Publication date
WO1985002454A1 (fr) 1985-06-06
FI834283L (fi) 1985-05-24
FI834283A0 (fi) 1983-11-23
FI84561B (fi) 1991-09-13

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